1. Field of the Invention
This invention relates to a method of treating flon-113 containing-waste gas which enables recovery and removal of flon-113 that is used widely and in large amounts among various flons from flon-113 containing-waste gas to prevent it from being released as it is in the air and also to an apparatus therefor.
2. Prior Art
Flons are generally low in toxicity, and are used in various fields such as electronics as a detergent, a solvent, etc.
However, there have occurred increase in the number of patients with dermal cancer, and destruction of ozone layer by flon gas which is said to be a cause of environmental abnormality and as a result it went so far that it has been decided in an international conference that consumption of flons should be reduced. Flons whose consumption is to be reduced include flon-11 (CC1.sub.3 F), flon-12 (CC1.sub.2 F.sub.2), flon-113 (C.sub.2 C1.sub.3 F.sub.3), flon-114 (C.sub.2 C1.sub.2 F.sub.4), and flon-115 (C.sub.2 C1F.sub.5). Particularly, flon-113 is used in large amounts. Reportedly, the amount of flon-113 released in the air as contained in waste gases is 60,000 tons a year. Further, it is practically difficult to get a substitute for flon-113 because of safety and price. Therefore, in many countries, efforts are directed to removal and recovery of flon-113 from waste gases containing it and reusing it.
Conventionally, recovery and reusing of flon-113 is performed by a method including adsorption with solid adsorbent such as activated carbon or the like, removal and recovery of flon-113.
However, the conventional method of adsorption and removal with a solid adsorbent is disadvantageous because heating at high temperatures or desorption with steam is required to recover absorbed flon-113, which results in increase in energy costs. Further, this treatment, flon-113 tends to decompose to give rise to acidic gases such as HC1, which corrodes the apparatus used and deteriorates the quality of flon-113 recovered. In addition, recovery of flon-113 is insufficient with the result that desorption efficiency is low and the method is economically undesirable.